454 MPI LX B3 28p

[MR252SS]

Having issue with motor not being able to attain max 4600 RPM. New remanufactured engine, computer diagnostics indicate everything is operating correctly, linkages were re-installed correctly, and 28 pitch props are original from manufacturer. With less than 20 gal.of fuel, alone, with no other substantial weight, boat will only attain 4100 RPM/51MPH. Anyone have any ideas?

 

[guyjg]

Dirty injector(s). Someone else recently had the same problem. Pull the injectors and have them tested. You could try disconnecting the electric plug on each injector while the engine is running. When the engine drops RPMS that injector is considered good. If there is no change in engine RPMS when an injector is unplugged, that is a defective injector or wiring.

 

[Docksidemarineservices]

Having issue with motor not being able to attain max 4600 RPM. New remanufactured engine, computer diagnostics indicate everything is operating correctly, linkages were re-installed correctly, and 28 pitch props are original from manufacturer. With less than 20 gal.of fuel, alone, with no other substantial weight, boat will only attain 4100 RPM/51MPH. Anyone have any ideas?

Does not mean they are the correct size. Sea Ray sells my boat with 19 pitch wheels. Way too big for my engines. If all checks out with your engine, reduce the prop pitch by 1 inch.

 

[MR252SS]

Thanks for the reply Chris and guyjg! Chris would reducing the prop by 1 inch reduce speed as well?